Reversible pointer and scale indicator



Sept 5, 195o H. BERNARD 2,521,564

y REVERSIBLE POINTER .AND SCALE INDICATOR Filed Oct. 24, 1946 2 Sheets-Sheet 1 /1| I l I I I I` I I I II|IIIII""I'l"|""|""|""|EI!1 I MMIII Munir@ .IIIIIIIIIIII' III" @l /10 I 4 Sept. '5, A1950 H. BERNARD REVERSIBLE POINTER AND scm INDICATOR 2 sheets-sheet 2 Filed Oct. 24, 1946 www M Y E N R O T T A Patented Sept. 5, 1950 REVERSIBLE POINTER AND SCALE INDICATOR Herbert Bernard, Belleville, N. J., assignor to Allen B. Du Mont Laboratories, Inc., a corporation of Delaware Passaic, N. J.,

Application October 24, 1946, Serial No. 705,445

3 Claims.

1 This invention relates to an indicating device in which a pointer is caused to move along a scale.

One of the objects of this invention is to provide means for indicating accurately by the sllde rule method, the positions to which va variable element is set, and in doing so to use the min-A imum of dial space.

Another object of this invention is to use both sides of a single slot in a slide rule indicator and to make the pointed traverse the slot rst on one side and then turn about on itself 180 and traverse the opposite side of said slot. In this way, linear travel equal to twice the length of the slot is attained.

Another object is to enable the indication to be spread in any desired pattern, such as several parallel slots connected by curves.

Another object is to permit the above objects to be attained with a motor drive, when desired.

These and other objects will be apparent. The invention will be described in connection with the tuning control and indicating mechanism of a very broad band, high frequency radio receiver in which a variable inductance tuning unit is used.

The invention may be understood from the following description and the drawings in which:

Fig. 1 is a section along I-I of Fig. 2.

Fig. 2 is a plan view of an embodiment of the invention.

Fig. 3 is a plan view with the dial face and backing plate removed.

Fig. 4 is a section along 4 4 of Fig. 2 on an enlarged scale.A

Fig. 5 is a perspective view of the portion of a chain where the pointer is attached.

Fig. 6 is a plan view of the dial face and pointer of another embodiment of the invention, and

Fig. 7 is a section along the line I-'I of Fig. 6 on an enlarged scale.

In the drawings reference character I indicates a dial iace that is provided with a slot 2. A scale 3 is inscribed along the slot 2 and a pointer 4 is caused to move along the slot 2. This pointer 4 is attached to a chain 5 at the sheet metal link 6. 'I'his chain 5 is supported by the sprocket 1 and the idler 8 and travels in the spaces between the guides 9 which are supported on the frame I0.

The sprocket 'I is carried on and driven by a shaft II which has a spherically shaped portion II which is supported in a bearing I2 that is carried by a slidable bracket I3 which is pressed by a compression spring I4 one end of which around an idler 22, back from this to be done without bears against the case I5 to keep the chain 5 taut. The bracket I3 is provided with a slot I 3' in which a screw I3" permits and limits movement of bracket I3 along the screw I3.

In the single slot device of Figs. 1 to 5 the various calibrations are laid out along both sides and around one end of the slot 2 as the scale\3 on the dial face I shown in Fig. 2. 'I'he pointer 4 will indicate on the scale 3 any rotation of shaft I I which may be suitably connected to any tuning device.

The sprocket and chain arrangement permits danger of slipping. The initial slack and any that may be introduced into the system through use or wear is taken up automatically .by the outward thrust of the spring I4 one end of which I5 and the other against the slidable bracket I3 that carries the shaft II in the bearing I2.

The pointer 4 is so attached to the chain 5 that at the pulley end it turns about on itself and traverses the opposite sido of the slot 2. This permits twice the length of scale to be provided in a given dial space as compared to the type of slide rule dial that traverses only one .side of its scale.

In the modification shown in Figs. 6 and 7 reference character I6 indicates a dial face in which a slot I'I is provided that has curved portions and straight portions. A scale I8 consisting of numerals is placed alongside the slot Il and a pointer I9 is caused to move along this slot. This pointer I9 is attached to a chain 2li which is driven by the sprocket 2| a. This chain passes around idlers 22-22c which are all supported by the frame 23. A spring pressed idler 22 is provided to keep the chain 20 taut.

'I'he sprocket 2Ia (Fig. 7) is carried by the sprocket shaft II which is mounted in the elongated bearing 2lb. It is driven from the shaft 29 of motor 30 by a gear train 24, 25, 26 and 21 through a slip clutch 28, which comprises compression spring 28.

The purpose of the slip clutch 28 is to prevent damage when the tuner reaches the end of its travel while power is still being applied to its shaft. This shaft 29 is adapted to be connected to the manual tuning control shaft 3| by means of a magnetic clutch 32.

With this invention very long scales can be utilized in a comparatively small space particularly as shown in Fig. 6. In this embodiment the pointer I9 travels across from left to right, right to left, then around another idler 22a, back from left to right bears against a wall of the case I around idler 12b and back from right to left to idler 22e.

In the modification shown in Figs. 6 and 7 the slide rule dial operates as described above, but the approximate setting is made by motor and the ilnal ilne adjustment is made by hand. The hand adjustment is accomplished by opening a switch (not shown) in the circuit that supplies current to the magnetic clutch 32, thus shutting off the supply of current to the magnet and so disengaging motor shaft 29 from the manual tuning knob shaft 3|. This prevents the knob on shaft 3| from turning at the speed of the motor with possible injury to the operator. The opening of this switch moves it into position to close a circuit through a snap switch not shown, to the motor 30 so that this motor rotates, driving the sprocket 21a through the gear train 21, 26, 25, 24, slip clutch 28 and shaft il. The switch is released 'by the operator when the pointer I9 has nearly reached the desired point on the scale. The motor contacts then open and the clutch contacts close engaging the clutch 32 and permitting the operator to use the manual tuning knob to operate the tuner and dial pointer by means of the shaft 3i, magnetic clutch 32, motor shaft 29, gear train 21, 26, and 24, slip clutch 28 and the shaft Il affording vernier tuning through this gear train. The bearing 2 lb of Fig. 7 for shaft I I' is xed. Chain tension is provided by ballcrank 33, pulley 22 and spring 34, as shown in Fig. 6.

The switch mentioned above may be arranged so that when the knob is turned to the left, the pointer travels counter-clockwise and when it is turned to the right, the pointer travels clockwise.

What is claimed is:

1. In an indicating device. a dial face having a slot therein, a scale alongside said slot, a pointer, and means comprising a motor and a magnetic slip clutch to move said pointer along said slot selectively in either of two directions to indicate one series of indicia while moving longitudinally in one direction and a diierent series of indicia while moving longitudinally in.

the opposite direction.

2. An indicating device comprising a plate 4 having a slot therein, a shaft extending toward said plate, a sprocket on the extending portion of said shaft, an idler behind said plate, a chain connecting said sprocket and idler, and a pointer carried by said chain and extending through said slot and having its end portion parallel to said plate whereby said shaft, idler and chain cause said pointer to traverse said slot on one side and then turn and traverse the opposite side of said slot.

3. An indicating device comprising a dial face having a slot therein, a scale on said dial face extending longitudinally adjacent said slot, a flexible power transmitting cable extending along said slot between the ends thereof around a guide positioned at one end of said slot and extending back toward the other end thereof, and a pointer attached to said cable and movable therewith to indicate sequentially and selectively all parts of said scale, said pointer making a 180 turn to reverse direction at the end of said slot.

HERBERT BERNARD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,041,059 Fox Oct. 15, 1912 1,391,279 Seignol Sept. 20, 1921 1,654,943 Nott Jan. 3, 1928 1,695,919 Gould Dec. 18, 1928 1,734,553 Bartlett Nov. 5, 1929 1,769,439 Lee July 1, 1930 1,776,842 Reinicke Sept. 30, 1930 1,809,509 Crossley et al June 9, 1931 1,827,959 Stahelin Oct. 20, 1931 2,081,752 Linsell May 25, 1937 2,185,482 Wallace Jan. 2, 1940 2,217,609 Bierman Oct. 8, 1940 2,295,387 Creager Sept. 8, 1942 FOREIGN PATENTS Number Country Date 350,654 Germany Mar. 23, 1922 496,837 Great Britain Dec. 7, 1938 760,500 France Feb. 23, 1934 

